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While each route of therapeutic drug delivery has its own advantages and limitations, oral delivery is often favored because it offers convenient painless administration, sustained delivery, prolonged shelf life, and often lower manufacturing cost. Its limitations include mucus and epithelial cell barriers in the gastrointestinal (GI) tract that can block access of larger molecules including Therapeutic protein or peptide-based drugs (TPPs), resulting in reduced bioavailability. This review describes these barriers and discusses different strategies used to modify TPPs to enhance their oral bioavailability and/or to increase their absorption. Some seek to stabilize the TTPs to prevent their degradation by proteolytic enzymes in the GI tract by administering them together with protease inhibitors, while others modify TPPs with mucoadhesive polymers like polyethylene glycol (PEG) to allow them to interact with the mucus layer, thereby delaying their clearance. The further barrier provided by the epithelial cell membrane can be overcome by the addition of a cell-penetrating peptide (CPP) and the use of a carrier molecule such as a liposome, microsphere, or nanosphere to transport the TPP-CPP chimera. Enteric coatings have also been used to help TPPs reach the small intestine. Key efficacious TPP formulations that have been approved for clinical use will be discussed.
Nirnoy Dan; Kamalika Samanta; Hassan Almoazen. An Update on Pharmaceutical Strategies for Oral Delivery of Therapeutic Peptides and Proteins in Adults and Pediatrics. Children 2020, 7, 307 .
AMA StyleNirnoy Dan, Kamalika Samanta, Hassan Almoazen. An Update on Pharmaceutical Strategies for Oral Delivery of Therapeutic Peptides and Proteins in Adults and Pediatrics. Children. 2020; 7 (12):307.
Chicago/Turabian StyleNirnoy Dan; Kamalika Samanta; Hassan Almoazen. 2020. "An Update on Pharmaceutical Strategies for Oral Delivery of Therapeutic Peptides and Proteins in Adults and Pediatrics." Children 7, no. 12: 307.
Background: Clindamycin’s bitter taste and odor is known to affect treatment adherence in children. Recently, a formulation of clindamycin HCl complexed with ion exchange resin IRP 69 was shown to mask the bitter taste. Because of the potential benefit of this formulation for children, a pilot study using a porcine model was conducted to evaluate its relative bioavailability. Methods: A randomized two-way cross-over study design using six (n = 6) healthy male piglets 10-12 kg was used to evaluate the absorption profiles and pharmacokinetic parameters of clindamycin from the resinate complex formulation (Test) compared to a commercialized reference suspension. A dose of 15 mg/kg was administered orally by gastric gavage to each piglet followed by repeated blood sampling over 12 hours. A wash-out period of 48 hours occurred between treatments. Plasma concentration vs. time data was analyzed by non-compartmental analysis. Results: The mean relative bioavailability of clindamycin from the resinate formulation was 78.8%. A two-tailed, paired Student t-test yielded a p-value <0.05 for AUCinfinity and Tmax parameters. A two one-sided test (TOST) suggested a difference in AUCinfinity and Cmax for the Test formulation compared to the Reference formulation according to the FDA’s criteria for bioequivalence. Conclusion: The bioavailability of clindamycin from this novel oral formulation supports continued evaluation of the drug in humans for potential pediatric applications.
Grace A. Goode; Santosh J. Wagh; David J. Irby; Dejian Ma; Richard F. Jacobs; Gregory L. Kearns; Hassan Almoazen. Bioavailability testing of a newly developed clindamycin oral suspension in a pediatric porcine model. Pharmaceutical Development and Technology 2019, 24, 1038 -1043.
AMA StyleGrace A. Goode, Santosh J. Wagh, David J. Irby, Dejian Ma, Richard F. Jacobs, Gregory L. Kearns, Hassan Almoazen. Bioavailability testing of a newly developed clindamycin oral suspension in a pediatric porcine model. Pharmaceutical Development and Technology. 2019; 24 (8):1038-1043.
Chicago/Turabian StyleGrace A. Goode; Santosh J. Wagh; David J. Irby; Dejian Ma; Richard F. Jacobs; Gregory L. Kearns; Hassan Almoazen. 2019. "Bioavailability testing of a newly developed clindamycin oral suspension in a pediatric porcine model." Pharmaceutical Development and Technology 24, no. 8: 1038-1043.
The purpose of this study is to develop an oral suspension of clindamycin resin complex for the potential use in pediatrics.
Alaadin Alayoubi; Baher Daihom; Hitesh Adhikari; Sanjay R Mishra; Richard Helms; Hassan Almoazen. Development of a taste-masked oral suspension of clindamycin HCl using ion exchange resin Amberlite IRP 69 for use in pediatrics. Drug Development and Industrial Pharmacy 2016, 42, 1579 -1589.
AMA StyleAlaadin Alayoubi, Baher Daihom, Hitesh Adhikari, Sanjay R Mishra, Richard Helms, Hassan Almoazen. Development of a taste-masked oral suspension of clindamycin HCl using ion exchange resin Amberlite IRP 69 for use in pediatrics. Drug Development and Industrial Pharmacy. 2016; 42 (10):1579-1589.
Chicago/Turabian StyleAlaadin Alayoubi; Baher Daihom; Hitesh Adhikari; Sanjay R Mishra; Richard Helms; Hassan Almoazen. 2016. "Development of a taste-masked oral suspension of clindamycin HCl using ion exchange resin Amberlite IRP 69 for use in pediatrics." Drug Development and Industrial Pharmacy 42, no. 10: 1579-1589.
Purpose: To evaluate the physicochemical characteristics of clindamycin HCl in a complex form (resinate) with ion exchange resin (Amberlite IRP69). Methods: Drug-resin complex was prepared by simple aqueous binding method. Drug binding study was carried out at different drug and resin concentrations. Several physicochemical characterization studies were conducted to evaluate the resinate complex. These studies included flow properties, in vitro drug release in SGF and SIF, DSC, TGA, Mass spectroscopy and XPRD evaluations. In addition, stability study of resinate complex was conducted at 25oC and 40oC for up to one month. Results: Clindamycin and Amberlite IRP69 have formed a complex (resinate) and has shown good flow properties, good thermal properties and chemical stability (short term over 4 weeks) at 25oC and 40oC. Clindamycin release profiles from resinate in SGF and SIF has shown immediate release characteristics and release in simulated saliva has shown dependence on water volume. Conclusion: The clindamycin stable complex with ion exchange resin (Amberlite IRP69) has the potential for further development as a compatible pediatric liquid formulation (suspension) or a fast disintegrating tablet.
Baher Daihom; Alaadin Alayoubi; Dejian Ma; Lijia Wang; Sanjay Mishra; Richard Helms; Hassan Almoazen. Development and physicochemical characterization of clindamycin resinate for taste masking in pediatrics. Drug Development and Industrial Pharmacy 2016, 42, 1600 -1608.
AMA StyleBaher Daihom, Alaadin Alayoubi, Dejian Ma, Lijia Wang, Sanjay Mishra, Richard Helms, Hassan Almoazen. Development and physicochemical characterization of clindamycin resinate for taste masking in pediatrics. Drug Development and Industrial Pharmacy. 2016; 42 (10):1600-1608.
Chicago/Turabian StyleBaher Daihom; Alaadin Alayoubi; Dejian Ma; Lijia Wang; Sanjay Mishra; Richard Helms; Hassan Almoazen. 2016. "Development and physicochemical characterization of clindamycin resinate for taste masking in pediatrics." Drug Development and Industrial Pharmacy 42, no. 10: 1600-1608.
Objective: To develop a fast dissolving film strip containing epinephrine HCl for the potential treatment of pediatric anaphylaxis. Methods: Four different films have been prepared by solvent casting technique where the percentages of the polymer (Lycoat RS720) were optimized. The polymer percentages were (20%, 25%, 27% and 30%) of the total formulation weighs. The thickness and elastic modulus of the optimized film was evaluated using dynamic mechanical analyzer. Epinephrine content uniformity was assessed using UV at wavelength 280 nm. For the dissolution test, fast dissolving films (FDFs) were evaluated in 500 Simulated Saliva, with 50 rpm. In vivo taste and disintegration evaluation was performed on six healthy volunteers. Results: Films formed by formulations 1, 2 and 3 were too sticky after drying, while formulation 4 that has 30% polymer content formed smooth, transparent, flexible and uniform film, and therefore, it was selected for further testing. The value of elastic modulus was determined at 1.325 MPa. The thickness of the film at different locations was measured at 0.29 mm. Drug content in film was measured at 93% ±10. More than 90% of epinephrine was released from the film within 7.2 min. Bitterness of epinephrine was masked efficiently according to volunteer’s comments with average disintegration time of 20 s. Conclusion: This study presents potential proof for using FDFs as a replacement therapy of epinephrine injections for pediatrics.
Alaadin Alayoubi; Lindsay Haynes; Hemlata Patil; Baher Daihom; Richard A Helms; Hassan Almoazen. Development of a fast dissolving film of epinephrine hydrochloride as a potential anaphylactic treatment for pediatrics. Pharmaceutical Development and Technology 2016, 22, 1012 -1016.
AMA StyleAlaadin Alayoubi, Lindsay Haynes, Hemlata Patil, Baher Daihom, Richard A Helms, Hassan Almoazen. Development of a fast dissolving film of epinephrine hydrochloride as a potential anaphylactic treatment for pediatrics. Pharmaceutical Development and Technology. 2016; 22 (8):1012-1016.
Chicago/Turabian StyleAlaadin Alayoubi; Lindsay Haynes; Hemlata Patil; Baher Daihom; Richard A Helms; Hassan Almoazen. 2016. "Development of a fast dissolving film of epinephrine hydrochloride as a potential anaphylactic treatment for pediatrics." Pharmaceutical Development and Technology 22, no. 8: 1012-1016.
The objective of this study was to evaluate the transdermal efficiency of iodide microemulsion in treating iodine deficiency using rats as an animal model. Animals were fed either iodine-deficient diet (20 μg/kg iodide) or control diet (200 μg/kg iodide) over a 17-month period. At month 14, iodide microemulsion was applied topically in iodine-deficient group and physiological evaluations of thyroid gland functions were characterized by monitoring the thyroid hormones (T3, T4), thyroid-stimulating hormone (TSH), iodide ion excretion in urine, and the overall rat body weights in both groups. Moreover, morphological evaluations of thyroid gland before and after treatment were performed by ultrasound imaging and through histological assessment. Prior to microemulsion treatment, the levels of T3, T4, and TSH in iodine-deficient group were statistically significant as compared to that in the control group. The levels of T3 and T4 increased while TSH level decreased significantly in iodine-deficient group within the first 4 weeks of treatment. After treatment, iodide concentration in urine increased significantly. There was no statistical difference in weight between the two groups. Ultrasound imaging and histological evaluations showed evidence of hyperplasia in iodine-deficient group. Topical iodide microemulsion has shown a promising potential as a novel delivery system to treat iodine deficiency.
Alaadin Alayoubi; Ryan D. Sullivan; Hao Lou; Hemlata Patel; Timothy Mandrell; Richard Helms; Hassan Almoazen. In Vivo Evaluation of Transdermal Iodide Microemulsion for Treating Iodine Deficiency Using Sprague Dawley Rats. AAPS PharmSciTech 2015, 17, 618 -630.
AMA StyleAlaadin Alayoubi, Ryan D. Sullivan, Hao Lou, Hemlata Patel, Timothy Mandrell, Richard Helms, Hassan Almoazen. In Vivo Evaluation of Transdermal Iodide Microemulsion for Treating Iodine Deficiency Using Sprague Dawley Rats. AAPS PharmSciTech. 2015; 17 (3):618-630.
Chicago/Turabian StyleAlaadin Alayoubi; Ryan D. Sullivan; Hao Lou; Hemlata Patel; Timothy Mandrell; Richard Helms; Hassan Almoazen. 2015. "In Vivo Evaluation of Transdermal Iodide Microemulsion for Treating Iodine Deficiency Using Sprague Dawley Rats." AAPS PharmSciTech 17, no. 3: 618-630.
The purpose of this study is to enhance the dissolution rate of prednisone by co-grinding with Neusilin to form a complex that can be incorporated into a mini-tablet formulation for pediatrics. Prednisone–Neusilin complex was co-grinded at various ratios (1:1, 1:3, 1:5, and 1:7). The physicochemical properties of the complex were characterized by various analytical techniques including: differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), scanning electron microscope (SEM), particle size, surface area, solubility, and dissolution rate. The co-grinded prednisone–Neusilin complex (1:7) was blended with other excipients and was formulated into a 2-mm diameter mini-tablet. The mini-tablets were further evaluated for thickness, weight, content uniformity, and dissolution rate. To improve taste masking and stability, mini-tablets were coated by dip coating with Eudragit® EPO solution. DSC and XRPD results showed that prednisone was transformed from crystalline state into amorphous state after co-grinding with Neusilin. Particle size, surface area, and SEM results confirmed that prednisone was adsorbed to Neusilin’s surface. Co-grinded prednisone–Neusilin complex (1:7) had a solubility of 0.24 mg/mL and 90% dissolved within 20 min as compared to crystalline prednisone which had a solubility of 0.117 mg/mL and 30% dissolved within 20 min. The mini-tablets containing co-grinded prednisone–Neusilin complex (1:7) exhibited acceptable physicochemical and mechanical properties including dissolution rate enhancement. These mini-tablets were successfully dip coated in Eudragit® EPO solution to mask the taste of the drug during swallowing. This work illustrates the potential use of co-grinded prednisone–Neusilin to enhance solubility and dissolution rate as well as incorporation into a mini-tablet formulation for pediatric use.
H. Lou; M. Liu; L. Wang; S. R. Mishra; W. Qu; J. Johnson; E. Brunson; Hassan Almoazen. Development of a Mini-Tablet of Co-Grinded Prednisone–Neusilin Complex for Pediatric Use. AAPS PharmSciTech 2013, 14, 950 -958.
AMA StyleH. Lou, M. Liu, L. Wang, S. R. Mishra, W. Qu, J. Johnson, E. Brunson, Hassan Almoazen. Development of a Mini-Tablet of Co-Grinded Prednisone–Neusilin Complex for Pediatric Use. AAPS PharmSciTech. 2013; 14 (3):950-958.
Chicago/Turabian StyleH. Lou; M. Liu; L. Wang; S. R. Mishra; W. Qu; J. Johnson; E. Brunson; Hassan Almoazen. 2013. "Development of a Mini-Tablet of Co-Grinded Prednisone–Neusilin Complex for Pediatric Use." AAPS PharmSciTech 14, no. 3: 950-958.
The purpose of this study is to evaluate the influence of sodium iodide, sodium chloride and sodium sulfate on the formation efficiency of sulfamerazine nanocrystals by wet ball milling.
Hao Lou; Min Liu; Wen Qu; James Johnson; Ed. Brunson; Hassan Almoazen. The influence of sodium salts (iodide, chloride and sulfate) on the formation efficiency of sulfamerazine nanocrystals. Pharmaceutical Development and Technology 2013, 19, 548 -555.
AMA StyleHao Lou, Min Liu, Wen Qu, James Johnson, Ed. Brunson, Hassan Almoazen. The influence of sodium salts (iodide, chloride and sulfate) on the formation efficiency of sulfamerazine nanocrystals. Pharmaceutical Development and Technology. 2013; 19 (5):548-555.
Chicago/Turabian StyleHao Lou; Min Liu; Wen Qu; James Johnson; Ed. Brunson; Hassan Almoazen. 2013. "The influence of sodium salts (iodide, chloride and sulfate) on the formation efficiency of sulfamerazine nanocrystals." Pharmaceutical Development and Technology 19, no. 5: 548-555.
Facial angiofibromas are dermatological manifestations of tuberous sclerosis complex, a neurocutaneous disorder characterized by excess cell growth and proliferation. Oral rapamycin has been used to treat visceral tuberous sclerosis–related tumors; however, the side effect profile of this medicine precludes its routine use in patients lacking significant internal involvement. The authors formulated a novel rapamycin cream that is easy to compound and apply, does not cause local or systemic side effects, and results in a dramatic improvement of facial angiofibromas.
James W. Wheless; Hassan Almoazen. A Novel Topical Rapamycin Cream for the Treatment of Facial Angiofibromas in Tuberous Sclerosis Complex. Journal of Child Neurology 2013, 28, 933 -936.
AMA StyleJames W. Wheless, Hassan Almoazen. A Novel Topical Rapamycin Cream for the Treatment of Facial Angiofibromas in Tuberous Sclerosis Complex. Journal of Child Neurology. 2013; 28 (7):933-936.
Chicago/Turabian StyleJames W. Wheless; Hassan Almoazen. 2013. "A Novel Topical Rapamycin Cream for the Treatment of Facial Angiofibromas in Tuberous Sclerosis Complex." Journal of Child Neurology 28, no. 7: 933-936.
Objective: To mask the bitterness of Chlorpheniramine Maleate via encapsulating drug into Eudragit EPO microparticles, and then incorporate these microparticles into orally disintegrating films (ODF) and orally disintegrating tablets (ODT) for pediatric uses. Methods: Spray drying of water-in-oil emulsion was utilized to encapsulate Chlorpheniramine Maleate into Eudragit EPO microparticles. Based on an orthogonal experimental design L9 (33), polynomial regression models were developed to evaluate correlation between microparticle properties (encapsulation efficiency and drug release) and variables (X1: weight ratio of polymer to drug, X2: volume ratio of oil to water and X3: Q-flow of spray dryer). ODF and ODT formulations were evaluated including weight variation, content uniformity, tensile strength, disintegration time, friability and dissolution profiles. The bitterness taste test was evaluated in 10 adult volunteers. Results and discussion: From polynomial regression analysis, the best values of variables leading to the optimized microparticles were X1 = 10, X2 = 3 and X3 = 45. The optimized microparticles were incorporated into ODF and ODT with satisfactory weight and drug content uniformity, and acceptable physical strength. Both dosage forms disintegrated immediately (less than 40 s) in simulated saliva solutions. The outcome of taste-masking test indicated that microparticles alleviated drug bitterness significantly; bitterness was not discernible with microparticles incorporated in ODT, whereas only slight bitterness was detected from microparticles incorporated into ODF. Conclusion: Both ODF and ODT are shown to be suitable vehicles for taste masked Chlorpheniramine Maleate microparticles with potential for pediatric uses.
Hao Lou; Min Liu; Wen Qu; Zheyi Hu; Ed Brunson; James Johnson; Hassan Almoazen. Evaluation of Chlorpheniramine Maleate microparticles in orally disintegrating film and orally disintegrating tablet for pediatrics. Drug Development and Industrial Pharmacy 2013, 40, 910 -918.
AMA StyleHao Lou, Min Liu, Wen Qu, Zheyi Hu, Ed Brunson, James Johnson, Hassan Almoazen. Evaluation of Chlorpheniramine Maleate microparticles in orally disintegrating film and orally disintegrating tablet for pediatrics. Drug Development and Industrial Pharmacy. 2013; 40 (7):910-918.
Chicago/Turabian StyleHao Lou; Min Liu; Wen Qu; Zheyi Hu; Ed Brunson; James Johnson; Hassan Almoazen. 2013. "Evaluation of Chlorpheniramine Maleate microparticles in orally disintegrating film and orally disintegrating tablet for pediatrics." Drug Development and Industrial Pharmacy 40, no. 7: 910-918.
The objective of this study was to develop a water-in-oil (w/o) microemulsion which can be utilized as a transdermal delivery for iodide ions. Several w/o microemulsion formulations were prepared utilizing Span 20, ethanol, Capryol 90®, and water. The selected formulations had 5%, 10%, 15%, 20%, and a maximum of 23% w/w water content. Potassium iodide (KI) was incorporated in all formulations at 5% w/v. Physicochemical characterizations were conducted to evaluate the structure and stability. These studies included: mean droplet size, pH, viscosity, conductivity, and chemical stability tests. In vitro human skin permeation studies were conducted to evaluate the diffusion of the iodide ion through human skin. The w/o microemulsion formulations were stable and compatible with iodide ions with water content ranging from 5% to 23% w/w. The addition of KI influenced the physicochemical properties of microemulsion as compared to blank microemulsion formulations. In vitro human skin permeation studies indicated that selected formulations improved iodide ion diffusion significantly as compared to control (KI solution; P value < 0.05). Iodide ions were entrapped within the aqueous core of w/o microemulsion. Span 20, ethanol and Capryol 90 protected the iodide ions against oxidation and formed a stable microemulsion. It is worth to note that according to Hofmeister series, iodide ions tend to lower the interfacial tension between water and oil and consequently enhance overall stability. This work illustrates that microemulsion system can be utilized as a vehicle for the transdermal administration of iodide.
Hao Lou; Ni Qiu; Catherine Crill; Richard Helms; Hassan Almoazen. Development of W/O Microemulsion for Transdermal Delivery of Iodide Ions. AAPS PharmSciTech 2012, 14, 168 -176.
AMA StyleHao Lou, Ni Qiu, Catherine Crill, Richard Helms, Hassan Almoazen. Development of W/O Microemulsion for Transdermal Delivery of Iodide Ions. AAPS PharmSciTech. 2012; 14 (1):168-176.
Chicago/Turabian StyleHao Lou; Ni Qiu; Catherine Crill; Richard Helms; Hassan Almoazen. 2012. "Development of W/O Microemulsion for Transdermal Delivery of Iodide Ions." AAPS PharmSciTech 14, no. 1: 168-176.
The objective of this study was to investigate the duration of biological effects of modified insulin glargine released from a novel biodegradable injectable gel in type II diabetic Zucker diabetic fatty (ZDF) rats. Modified insulin glargine was purified from the marketed formulation by process of dialysis followed by freeze-drying, and the purity was confirmed by the single peak, corresponding to insulin glargine in the HPLC chromatogram. To determine and to compare the biological activity of purified insulin glargine with marketed formulation, it was suspended in isotonic saline solutions and administered subcutaneously to ZDF rats at a dose of 10 IU/kg of insulin and the blood glucose levels were measured. The blood glucose levels of ZDF rats after a subcutaneous injection of a suspension of purified insulin glargine decreased below 200 mg/dL within 2 h and remained at this level up to 6 h, then steadily raised above 400 mg/dL in 12 h. Insulin glargine particles were loaded into a novel biodegradable injectable gel formulation prepared from a blend of polylactic-co-glycolic acid (PLGA) and biocompatible plasticizers. Approximately 0.1 mL of insulin glargine-loaded gel prepared with PLGA was administered subcutaneously to the ZDF rats, and blood glucose levels were measured. The PLGA gel formulations prepared with insulin glargine particles had duration of action of 10 days following a single subcutaneous injection. The addition of zinc sulfate to the formulations prepared with purified insulin glargine particles further slowed down the drop in blood glucose concentrations.
Om Anand; Hassan Almoazen; Nitin Mehrotra; James Johnson; Atul Shukla. Controlled Release of Modified Insulin Glargine from Novel Biodegradable Injectable Gels. AAPS PharmSciTech 2012, 13, 313 -322.
AMA StyleOm Anand, Hassan Almoazen, Nitin Mehrotra, James Johnson, Atul Shukla. Controlled Release of Modified Insulin Glargine from Novel Biodegradable Injectable Gels. AAPS PharmSciTech. 2012; 13 (1):313-322.
Chicago/Turabian StyleOm Anand; Hassan Almoazen; Nitin Mehrotra; James Johnson; Atul Shukla. 2012. "Controlled Release of Modified Insulin Glargine from Novel Biodegradable Injectable Gels." AAPS PharmSciTech 13, no. 1: 313-322.
Jon E Sprague; Daniel Aistrope; Hassan Almoazen; Anthony C. Samsa; Charles N. May; Muhammad Abdul Hadi; Long C. Ming; Lee W. Leng; Shazwani Shaharuddin; Aishah Adam. Letters. American Journal of Pharmaceutical Education 2010, 74, 1 .
AMA StyleJon E Sprague, Daniel Aistrope, Hassan Almoazen, Anthony C. Samsa, Charles N. May, Muhammad Abdul Hadi, Long C. Ming, Lee W. Leng, Shazwani Shaharuddin, Aishah Adam. Letters. American Journal of Pharmaceutical Education. 2010; 74 (2):1.
Chicago/Turabian StyleJon E Sprague; Daniel Aistrope; Hassan Almoazen; Anthony C. Samsa; Charles N. May; Muhammad Abdul Hadi; Long C. Ming; Lee W. Leng; Shazwani Shaharuddin; Aishah Adam. 2010. "Letters." American Journal of Pharmaceutical Education 74, no. 2: 1.
Hassan Almoazen; Anthony C. Samsa; Charles N. May. Why Analytical Testing Is Needed in Pharmaceutical Compounding. American Journal of Pharmaceutical Education 2010, 74, 1 .
AMA StyleHassan Almoazen, Anthony C. Samsa, Charles N. May. Why Analytical Testing Is Needed in Pharmaceutical Compounding. American Journal of Pharmaceutical Education. 2010; 74 (2):1.
Chicago/Turabian StyleHassan Almoazen; Anthony C. Samsa; Charles N. May. 2010. "Why Analytical Testing Is Needed in Pharmaceutical Compounding." American Journal of Pharmaceutical Education 74, no. 2: 1.
Hassan Almoazen; Himanshu Bhattacharjee; Anthony C Samsa; Steve Pate. Stability of Mesna in ReadyMed Infusion Devices. Annals of Pharmacotherapy 2010, 44, 224 -225.
AMA StyleHassan Almoazen, Himanshu Bhattacharjee, Anthony C Samsa, Steve Pate. Stability of Mesna in ReadyMed Infusion Devices. Annals of Pharmacotherapy. 2010; 44 (1):224-225.
Chicago/Turabian StyleHassan Almoazen; Himanshu Bhattacharjee; Anthony C Samsa; Steve Pate. 2010. "Stability of Mesna in ReadyMed Infusion Devices." Annals of Pharmacotherapy 44, no. 1: 224-225.
An attempt to evaluate the kinetically effective critical micelle concentration CMC of sodium dodecyl sulfate (SDS) in micellar solutions and in O/W emulsions at 40°C and pH 9 utilizing the pseudo first order rate constant of benzyl acetate hydrolysis was implemented. The critical micelle concentration of SDS in micellar solutions was determined by both surface tension measurements utilizing Wilhelmy plate technique and by rate constant of hydrolysis. Hydrolysis reaction of benzyl acetate was monitored in surfactant solutions as well as in o/w emulsions as a function of time. Emulsion droplets were controlled using microfluidizer 110 T and oily droplets were separated from the emulsion by ultracentrifugation at (11,500 rpm or 9,800 g) prior to analysis by high performance liquid chromatography. The value of the critical micelle concentration (CMC) in micellar solutions in the presence of benzyl acetate as determined from the Wilhelmy plate technique was 7.8 × 10−4 moles/L (CMC in micellar solution was 10 times lower than the value in literature due to use of buffer) while the CMC as determined from the kinetic study was 8.8 × 10−4 moles/L. In emulsion systems, using 5% mineral oil, the CMC value was 8.6 × 10−3 moles/L and at 10% oil, the value doubled to 1.73 × 10−2 moles/L. The above results indicate that kinetics can be used to determine CMC in micellar solutions and in o/w emulsions.
Hassan Almoazen; Anthony P. Simonelli. Determining the Critical Micelle Concentration in O/W Emulsion Using the Rate Constant of Hydrolysis for Benzyl Acetate. Journal of Dispersion Science and Technology 2008, 29, 958 -965.
AMA StyleHassan Almoazen, Anthony P. Simonelli. Determining the Critical Micelle Concentration in O/W Emulsion Using the Rate Constant of Hydrolysis for Benzyl Acetate. Journal of Dispersion Science and Technology. 2008; 29 (7):958-965.
Chicago/Turabian StyleHassan Almoazen; Anthony P. Simonelli. 2008. "Determining the Critical Micelle Concentration in O/W Emulsion Using the Rate Constant of Hydrolysis for Benzyl Acetate." Journal of Dispersion Science and Technology 29, no. 7: 958-965.
Geoffrey C. Wall; Hassan Almoazen; Erik D. Maki. Lack of a physicochemical interaction between metronidazole and cholestyramine. International Journal of Antimicrobial Agents 2007, 30, 372 -374.
AMA StyleGeoffrey C. Wall, Hassan Almoazen, Erik D. Maki. Lack of a physicochemical interaction between metronidazole and cholestyramine. International Journal of Antimicrobial Agents. 2007; 30 (4):372-374.
Chicago/Turabian StyleGeoffrey C. Wall; Hassan Almoazen; Erik D. Maki. 2007. "Lack of a physicochemical interaction between metronidazole and cholestyramine." International Journal of Antimicrobial Agents 30, no. 4: 372-374.
Madiha B Sidhom; Nadya Rivera; Hassan Almoazen; David R Taft; Harold L Kirschenbaum. Stability of sotalol hydrochloride in extemporaneously prepared oral suspension formulations. International journal of pharmaceutical compounding 2005, 9, 402 -6.
AMA StyleMadiha B Sidhom, Nadya Rivera, Hassan Almoazen, David R Taft, Harold L Kirschenbaum. Stability of sotalol hydrochloride in extemporaneously prepared oral suspension formulations. International journal of pharmaceutical compounding. 2005; 9 (5):402-6.
Chicago/Turabian StyleMadiha B Sidhom; Nadya Rivera; Hassan Almoazen; David R Taft; Harold L Kirschenbaum. 2005. "Stability of sotalol hydrochloride in extemporaneously prepared oral suspension formulations." International journal of pharmaceutical compounding 9, no. 5: 402-6.
To evaluate the effect of pH on solubility and dissolution rates of a model weak base, haloperidol, and two different salt forms, hydrochloride and mesylate.pH-solubility profiles were determined by using haloperidol base, haloperidol hydrochloride, and haloperidol mesylate as starting materials; concentrated or diluted HCl or NaOH solutions were added to aqueous suspensions of solids to adjust pH to desired values. Intrinsic dissolution rates were determined using intrinsic dissolution apparatus under various pH-stat conditions. Further, approximation of diffusion layer pH was estimated from that of 10% w/w slurries of drug substances in dissolution media, which were used to correlate with intrinsic dissolution rates of haloperidol and its salt forms under different pHs.pH-solubility profiles of haloperidol base and its HCl salt were similar, while when the mesylate salt was used as starting material, it exhibited a higher solubility between pH 2 and 5. The higher solubility of the mesylate salt at pH 2-5 is attributed to its higher solubility product (K(sp)) than that of the hydrochloride salt. The pH-solubility profiles indicated a pH(max) (pH of maximum solubility) of approximately 5, indicating that the free base would exist as the solid phase above this pH and a salt would be formed below this pH. Below pH 1.5, all solubilities were comparable due to a conversion of haloperidol base or the mesylate salt to the HCl salt form when HCl was used as the acidifying agent. These were confirmed by monitoring the solid phase by differential scanning calorimeter. When their dissolution rates are tested, dissolution rates of the mesylate salt were much higher than those of the free base or the HCl salt, except at very low pH (<2). Dissolution rates of free base and HCl salt also differed from each other, where that of HCl salt exhibits higher dissolution rates at higher pHs. A direct correlation of dissolution rate with solubility at diffusion layer pH at the surface of dissolving solid was established for haloperidol, its hydrochloride, and mesylate salts.Using pH-solubility and pH-dissolution rate interrelationships, it has been established that diffusion layer pH could be used to explain the observed rank order in dissolution rates for different salt forms. A non-hydrochloride salt, such as a mesylate salt, may provide advantages over a hydrochloride salt due to its high solubility and lack of common ion effect unless at very low pH.
Shoufeng Li; Suiming Wong; Sundeep Sethia; Hassan Almoazen; Yatindra M. Joshi; Abu T. M. Serajuddin. Investigation of Solubility and Dissolution of a Free Base and Two Different Salt Forms as a Function of pH. Pharmaceutical Research 2005, 22, 628 -635.
AMA StyleShoufeng Li, Suiming Wong, Sundeep Sethia, Hassan Almoazen, Yatindra M. Joshi, Abu T. M. Serajuddin. Investigation of Solubility and Dissolution of a Free Base and Two Different Salt Forms as a Function of pH. Pharmaceutical Research. 2005; 22 (4):628-635.
Chicago/Turabian StyleShoufeng Li; Suiming Wong; Sundeep Sethia; Hassan Almoazen; Yatindra M. Joshi; Abu T. M. Serajuddin. 2005. "Investigation of Solubility and Dissolution of a Free Base and Two Different Salt Forms as a Function of pH." Pharmaceutical Research 22, no. 4: 628-635.
Para-aminohippuric acid (PAH), an indicator of renal plasma flow, is a commonly used marker of organic anion transport by the kidney. An analytical method for PAH using HPLC was developed. The method is simple, fast and requires a minimum amount of organic solvent. Sample preparation involved protein precipitation with zinc sulfate. Para-amino benzoic acid was utilized as an internal standard (IS). Chromatography was performed using a reversed-phase phenyl column with UV detection at a wavelength of 254 nm. Mobile phase consisted of 0.1 M acetic acid and acetonitrile (99:1) at a flow rate of 1 ml/min. The assay was validated over a standard concentration range from 1 to 25 μg/ml. Accuracy, precision, reproducibility and specificity of the method was established with coefficients of variation 0.99). The assay was used to study the effect of aging on PAH excretion in the isolated perfused rat kidney model. Experiments were conducted in kidneys from young (2–3 months, n=6), adult (6–9 months, n=5) and aged (12–16 months, n=3) male Sprague–Dawley rats at an initial drug concentration of 20 μg/ml. Significant differences in kidney function (e.g. glomerular filtration rate and glucose reabsorption) were observed in aged kidneys. Despite a 5-fold reduction in glomerular filtration rate, PAH renal clearance (kidney weight-corrected) decreased by only 2-fold in aged (2.2±0.42 ml/min per gram) compared to young (4.6±0.70 ml/min per gram, P<0.05) rats. Furthermore, renal excretion ratio was significantly higher in aged rats (27±8.0 vs. 15±5.0, P<0.05). These preliminary findings challenge the ‘Whole Nephron Hypothesis’ that assumes parallel reductions in renal filtration and secretory capacity secondary to disease or aging.
Ishani A Savant; Michelle Kalis; Hassan Almoazen; Stephan R Ortiz; Malaz AbuTarif; David R Taft. Alternative high-performance liquid chromatographic assay for p-aminohippuric acid (PAH): effect of aging on PAH excretion in the isolated perfused rat kidney. Journal of Pharmaceutical and Biomedical Analysis 2001, 26, 687 -699.
AMA StyleIshani A Savant, Michelle Kalis, Hassan Almoazen, Stephan R Ortiz, Malaz AbuTarif, David R Taft. Alternative high-performance liquid chromatographic assay for p-aminohippuric acid (PAH): effect of aging on PAH excretion in the isolated perfused rat kidney. Journal of Pharmaceutical and Biomedical Analysis. 2001; 26 (5-6):687-699.
Chicago/Turabian StyleIshani A Savant; Michelle Kalis; Hassan Almoazen; Stephan R Ortiz; Malaz AbuTarif; David R Taft. 2001. "Alternative high-performance liquid chromatographic assay for p-aminohippuric acid (PAH): effect of aging on PAH excretion in the isolated perfused rat kidney." Journal of Pharmaceutical and Biomedical Analysis 26, no. 5-6: 687-699.